Smoking filters

Abstract

A filter for cigarettes or the like has an elongated tubular shell one interior end portion of which may be shaped to define a seat of a diameter to frictionally receive an end portion of a cigarette and longitudinally of that seat being shaped to define a tubular wall of predetermined cross-section and partially closed by a transverse wall in which is defined a central aperture. An air inlet extends through the outer wall of the shell. A filter element is of a porous material which is inhibitive to the passage of substances such as tar and nicotine. The element is in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open. A laterally projecting shoulder is defined on the sleeve to have the aforementioned predetermined cross-section so as to seat frictionally within the tubular wall and against the transverse wall with a portion of the sleeve projecting through the aperture.

We claim: 
     
       1. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a rigidified porous plastic material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one integral and commonly-formed end of which is closed and the other end of which is open; means supporting said filter element within said tubular shell beyond said coupling.   
     
     
       2. A filter as defined in claim 1 in which said one end portion of said shell is turned re-entrantly inward and shaped to define a seat to receive frictionally an end portion of a smoking device. 
     
     
       3. A filter as defined in claim 2 in which said seat faces said one end of said tubular shell. 
     
     
       4. A filter as defined in claim 1 in which said one end of said tubular shell is formed to define a laterally-projecting rim. 
     
     
       5. A filter as defined in claim 1 in which the other end of said tubular shell is partially closed to define an outlet opening having a margin therearound. 
     
     
       6. A filter as defined in claim 5 in which said element is disposed with its one end in facing relationship with said outlet opening and in which said element includes a longitudinally-extending abutment, projecting away from said sleeve, engageable with the margin of said outlet opening and defining flow passages in communication through said opening. 
     
     
       7. A filter as defined in claim 1 in which said element includes externally a series of circumferentially-spaced longitudinal flutes. 
     
     
       8. A filter as defined in claim 7 in which the lands between said flutes have a diameter slightly less than the interior of said tubular shell to allow smoke and air passage between the flutes and the interior of said tubular shell. 
     
     
       9. A filter as defined in claim 7 in which said element includes a laterally projecting rib at the upstream end of said flutes that is engageable with the interior of said tubular shell, and in which said air inlet is located downstream of said rib. 
     
     
       10. A filter as defined in claim 1 and further comprising: said element including externally a series of circumferentially spaced longitudinal flutes;   said element including a laterally-projecting rib at the upstream end of said flutes that is engageable with the interior of said tubular shell, said air inlet being located downstream of said ribs;   and said air inlet being located upstream of said rib.   
     
     
       11. A filter as defined in claim 1 which further includes an elongated hollow housing receptive of said tubular shell for storage therein. 
     
     
       12. A filter as defined in claim 11 in which said housing includes a clip externally mounted thereon and disposed to engage a medium disposed between the exterior of said housing and said clip. 
     
     
       13. A filter as defined in claim 11 in which said housing includes a member, projecting longitudinally outward therefrom and of a diameter to be insertable through an end of said tubular shell to dislodge said filter element from said tubular shell. 
     
     
       14. A filter as defined in claim 11 in which said housing includes a barrel receptive of said smoking filter for storage and a removable cap for closing said barrel. 
     
     
       15. A filter as defined in claim 11 in which said housing is of a length sufficient to store, in addition to said smoking filter, an additional one of said filter elements. 
     
     
       16. A filter as defined in claim 1 in which said shell is generally of rectangular cross-section but with its corners depressed inwardly. 
     
     
       17. A filter as defined in claim 1 in which said material initially is of a light color subject to becoming increasingly darker upon collection therein of said substances during usage. 
     
     
       18. A filter as defined in claim 1 in which said other end of said tubular shell defines and outlet opening and in which said one end of said filter element is aligned with said opening to permit disengagement of said filter element from said tubular wall by means of a tool inserted through said opening. 
     
     
       19. A filter as defined in claim 1 in which said material of said element is a plastic and in which said element is formed by injecting a powder of said material into a mold and subjected to heat for a period of time sufficient to coalesce said powder into the shape of said element while developing limited porosity therein to the flow of said smoke. 
     
     
       20. A filter as defined in claim 1 in which said other end of said tubular shell defines an outlet opening, and which further comprises means, including a contour defined in said tubular wall, defining a passage between said coupling and said outlet opening in bypass of said filter element. 
     
     
       21. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   said tubular wall being partially closed by a transverse wall in which is defined a central aperture;   means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section to seat within said tubular wall and against said transverse wall with a portion of said sleeve projecting through said aperture;   and said shoulder being of a size to seat frictionally within said tubular wall.   
     
     
       22. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   said tubular wall being partially closed by a transverse wall in which is defined a central aperture;   means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section to seat within said tubular wall and against said transverse wall with a portion of said sleeve projecting through said aperture;   and the interior lateral dimension of said tubular shell being changed in successive steps to define said coupling and to define a seat for said shoulder.   
     
     
       23. A filter as defined in claim 22 in which the thickness of said tubular shell is changed correspondingly to establish said steps. 
     
     
       24. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   said tubular wall being partially closed by a transverse wall in which is defined a central aperture;   means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section to seat within said tubular wall and against said transverse wall with a portion of said sleeve projecting through said aperture;   and said shoulder being effectively located in a position encircling said other end of said sleeve.   
     
     
       25. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   said tubular wall being partially closed by a transverse wall in which is defined a central aperture;   means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section to seat within said tubular wall and against said transverse wall with a portion of said sleeve projecting through said aperture;   and said air inlet being effectively located downstream of said shoulder.   
     
     
       26. A smoking filter comprising: an elongated tubular shell one interior end portion of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section selected to seat within said tubular wall;   the material of said element being molded from a powder;   and said shoulder being compacted during molding to a density greater than that of said sleeve.   
     
     
       27. A smoking filter comprising: an elongated tubular shell one interior end portin of which is shaped to define a coupling to a smoking device and longitudinally of said coupling being shaped to define a tubular wall of predetermined cross-section;   means defining an air inlet through the outer wall of said shell;   a filter element, of a porous material inhibitive to the passage of substances in said smoke and in the form of an elongated hollow sleeve one end of which is closed and the other end of which is open, disposed within said tubular shell beyond said coupling;   said tubular wall being partially closed by a transverse wall in which is defined a central aperture;   and means on the exterior of said sleeve defining a laterally projecting shoulder of a cross-section to seat within said tubular wall and against said transverse wall with a portion of said sleeve projecting through said aperture.   
     
     
       28. A filter as defined in claim 27 in which said sleeve includes externally a series of circumferentially-spaced longitudinal flutes.